Apparatus for knitting selvages on narrow webs



July 19, 1966 E. H.- JOHNSON 3,261,376

APPARATUS FOR KNITTING SELVAGES 0N NARROW WEBS Filed July 9. 1965 5 Sheets-Sheet 1 INVENTOR ATTORNEYS ELMER H. JOHNSON BY 6g @7 fin a .w 1255 w fir/z/Z P 3 .5 :5 EC Cl July 19, 1966 E. H JOHNSON APPARATUS FOR KNITTING SELVAGES 0N NARROW WEBS 5 Sheets-Sheet 2 Filed July 9. 1965 FIG. 5

INVENTOR ELM ER H. JOHNSON ATTORNEYS July 19, 1966 E. H. JOHNSON APPARATUS FOR KNITTING SELVAGES ON NARROW WEBS 5 Sheets-Sheet 5 Filed July 9. 1965 FIG. 7

FIG. IO

INVENTOR.

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ELM ER H. JOH NSO N ATTORN EYS United States Patent 3,261,376 APPARATUS FOR KNITTING SELVAGES ON NARROW WEBS Elmer H. Johnson, Sharon, Mass., assignor to John D. Riordan, Hopkinton, Mass., and Gertrude C. Libby,

Stoughton, Mass., trustees of the Libby Family trusts Filed July 9, 1965, Ser. No. 470,750 6 Claims. (Cl. 139-124) This application is a continuation-in-part of my copendin-g application Serial No. 248,519, filed December 31, 1962 and subsequently abandoned.

The invention relates to shuttleless narrow web looms of the type which project loops of weft yarn through the shed of warp yarns alternately from opposite sides of the shed. For this purpose a finger having an eye in the end thereof is provided on each side of the shed. These fingers are operated alternately to swing through the shed so as to lay loops of weft yarn therein, the end of each loop being caught by a knitting needle at the further side of the shed and drawn through the previous loop caught by the needle, the latter loop thereupon being cast off. Shuttleless looms of this kind can operate very rapidly, but the knitting needles which form the selvages of the web are subject to frequent breakage, especially when relatively heavy weft yarns are employed, this resulting in defects in the web and much loss of production when the loom has to be stopped to replace broken needles. If latch needles are used, it'is the latch which is the vulnerable part. In the case of a spring needle, it is the spring beard.

According to the present invention, a more durable needle is provided which has neither latch nor sprin'g beard, the needle consisting of a simple rigid book which is so mounted as to be rotatable about the axis of its shank as well as being longitudinally reciprocable. By rotating the needle 180 back and forth in timed relation to its reciprocation, each new 100p of yarn which is placed on the needle can be drawn through the standing loop so as to cast off the latter, as more fully hereinafter described. As the delicate parts of the needle have been eliminated, the needle is durable and operates indefinitely without breakage.

For a more complete understanding of the invention, reference may be had to the following description thereof, and to the drawings, of which FIGURE 1 is a perspective view of the principal parts of the weft-laying mechanism of a narrow-web loom;

FIGURE 2 is a front elevation of the cams for rotating the selvage needles and reciprocating two yarn pressers which cooperate with the selvage needles;

FIGURE 3 is a perspective view of one of the selvage needles and one of the pressers with mechanism connecting them with the operating cams;

FIGURE 4 is an enlarged outline of one of the cams shown in FIGURE 3;

FIGURE 5 is a front elevation, on a larger scale, of the needle shown in FIGURE 3;

FIGURE 6 is a side elevation of the same;

FIGURES 7 to 12 are enlarged views of the needle in successive positions of operation with relation to the fabric which is being woven;

FIGURES 13 and 14 are plan views, on a smaller scale, of the needles and weft-laying fingers forming a web.

The weft-laying mechanism illustrated in FIGURE 1 is part of a narrow web loom having warp shed forming means and ifingers for thrusting loops of weft yarn through the shed alternately from opposite sides thereof. Fragments of the main frame 20 which supports the apparatus are shown. A revoluble reed 22 is provided to beat up the loops of weft yarn laid in the shed 3,261,376 Patented July 19, 1966 "ice of warp threads by fingers 24 and 26, each of which has an eye 28 near its free end for the weft yarn. Each of the weft-laying fingers extends slidably through a guide member 30 which is rockable about a vertical axis. One end of the finger 24 is attached to a crank 32 which is mounted on a vertical crank-shaft 34 to revolve in a counter-clockwise direction. The finger 26 is similarly attached at one end to a crank 36 on a vertical crank-shaft 38 which revolves in a clockwise direction. The shafts 34 and 38 are rotated at equal speeds with the cranks 32 and 36 in opposite phase so that the free ends of the fingers 24 and 26 sweep through the shed in alternation,

carrying loops of weft yarn to the opposite sides of the shed where the ends of the loops are caught by knitting needles 40 and 42 which are disposed in grooves in walls 43 of the main frame and are operated to knit the end of each loop through the loop previously caught by the needle. The chains of loops thus formed constitute the selvages of the web.

Narrow web looms of the type described are usually operated at high speeds, and the selvage needles are subject to a high rate of breakage with a consequent reduction in the output of the loom. According to the present invention, needles of the standard types are replaced by needles which are more durable since each consists of a shank with a rigid hook at the end, no latch or spring beard being employed. For the operation of this simplified needle, provision is made for a prescribed series of rotative movements on its long axis through an angle of 180 and reverse, in addition to the usual longitudinal reciprocating movements.

As shown in FIGURE 3, for rotative movements the needle 42 is attached to an elongated coaxial pinion 44 so that the needle and pinion move as a unit. The pinion meshes with a vertical rack 46 which is attached at its lower end to a lever '48 pivoted at its other end 50. A cam follower 52 on the lever 48 is pressed by a spring 53 against a disk cam 54 which is mounted on a cam shaft 56. When the arm 48 is raised or lowered by the cam 54, the rack 46 rotates the pinion 44 and the needle 42 in one direction or the other through an angle of 180, the angle of rotation of the needle from its normal angular position being represented by the radial distance between the cam outline shown in FIGURE 4 and the circular are 59 shown in a broken line.

For longitudinal reciprocation of the needle, the hub 58 of the pinion 44 is rotatable in a block 60 but is not axially movable relatively thereto. The block 60 is linked to an arm 62 which is pivoted at 64 and is rocked by an eccentric strap 66 embracing an eccentric (not shown) on the crank shaft 38. The longitudinal movements of the needle 42 are thus made in timed relation to the movements of the finger 26.

At the sides of the web are yarn pressers 68 and 69. Each of these pressers is mounted on a vertical rod 70 which is movable down and up by a spring 71 and a cam 72 acting through a cam follower 74 on an arm 76 pivoted at 78. The function of the pressers is to press the weft yarn which passes through the finger on the same side of the shed into the book of the adjacent needle so that both weft yarns will be knitted together to form a smoother, straighter selvage which is locked since a break in either yarn will not result in raveling.

The needle 40 on the other side of the web is operated by mechanism which is a mirror image of that which operates the needle 42, as described.

Enlarged views of the needle 42 in an upright position are shown in FIGURES 5 and 6. The shank 80 of the needle is preferably but not necessarily round. The upper portion 82 which terminates in a hook 84 is either widened slightly or, as shown, is given a slight lateral bend so C that when new loops of yarn are drawn down by the needle through the loops already on the shank of the needle, the latter loops will be widened momentarily for easier passage of the new loops therethrough before the old loops are cast off.

The front of the upper portion 82 of the needle is shaved to form a fiat face 85 which extends to the extremity of the hook 84 and results in a tapering thickness of the portion 82 as is evident in FIGURE 6. The back 86 of the hook slopes forward and upward, and the beak 87 of the hook is substantially parallel to it so that the throat 88 of the hook also slopes forward and upward to retain a loop of yarn in the throat when the needle is facing the loop, as in FIGURES 9 and 10. The beak 87 of the hook terminates in a point which is well within the cylindrical space defined by the walls of the shank 80.

Successive positions of the needle 42 as it moves through a cycle are shown in FIGURES 7 to 12. Since the needles 40, 42 are horizontal, or nearly so, in the machine, these figures may be regarded as plan views. In a cycle of its operation the needle 42 turns to the left from the position shown in FIGURE 7 to that shown in FIGURE 8 and on to the position shown in FIGURE 9 after catching the yarn F at 94 and the yarn F at 96. After it has been retracted toward the front of the machine to the position shown in FIGURE 10 to cast off the loops on its shank, it is rotated to the right to the position shown in FIGURE 11 and is then advanced to move the loops 94, 96 onto the shank of the needle and to catch new loops of yarn as indicated in FIGURE 12. To accommodate the hook 84 of the needles 40, 42 when they are retracted, the rear ends of the walls 43 are notched as at 90, and a thin plate 92 is mounted against the inner face of each wall with its rear edge flush with the rear edge of the wall against which it is mounted. The plates 92 are thus laterally offset from the paths of the hooks of the needles so that there is no clashing between the hooks and the plates. The rear edges of the plates 92, however, serve as knockover elements to insure that the yarn loops on the shanks of the needles will be cast off when the needles are retracted after receiving new loops in their hooks.

The cam shaft 56 makes one revolution for each operation of the corresponding weft-laying finger 26. When the parts are in the positions shown in FIGURE 13, the finger 24 has been swung through the warp shed to catch its loop of weft or filling yarn F on the hook of the needle 42 as retraction of the needle is started, the end portion thereof being just below the finger 24 and above the stretch of yarn F leading from the fell of the fabric to the bottom of the hole 28 in the end of the finger 24. The hook 84 of the needle 42 is then facing outward so that the end of the loop is caught in the hook of the needle. At this moment the finger 26 is about to be projected rearward alongside the shed toward the position shown in FIGURE 14 so that enough weft yarn F will be drawn through its eye 28 thereof for a loop to be carried through the shed by a sweeping movement of this finger to the left. During this rearward movement of the finger 26 and the rapid sweep through the shed, the needle 42 is retracted from the position shown in FIGURE 7 to that shown in FIGURE 10. During this retraction the needle is rotated toward the left as the cam follower 52 moves 011 the cam 54 from the 0 point to the 180 point, (FIGURE 4). The turning movement is gradual, as indicated by the radial distance between the solid line are 54 and the broken line are 57, until the cam follower reaches the 170 point whereupon the remaining rotation is rapid to the position wherein the hook 84 faces the fabric as in FIGURE 10 and back again to face away from the fabric as in FIGURE 11. The needle then starts rearward as the cam follower 52 reaches the ZOO-degree point on the cam 54. The needle hook 84 faces outward until the cam follower passes the 0- degree point, the position of the needle then being as shown in FIGURE 12, ready to catch the weft yarn F from the finger 26. Since the needles are axially driven by connections with eccentrics (not shown) rotated by the shafts 38 and 34 respectively, the axial movements of the needles are approximately simple harmonic motion. This means that the axial movements of the needle 42, for example, near the ends of its axial strokes are relatively slow so that when the needle is at the rearward end of its stroke to catch the weft yarns in its hook, its axial movement changes slowly from rearward projecting movement to forward retracting movement, and at that moment its rotation begins slowly. When the hook enters the notch 98 to cast off the weft loops from the shank of the needle, the axial movement of the needle is slow but as it begins to move past the edge of the knockover plate R2 it quickly completes the half-turn which was begun slowly at the beginning of its retractive movement. Thus the loops on the shank of the needle slide off the back of the hook and do not catch on the beak 87. The needle is then quickly rotated at full half-turn in the opposite direction While the edge of the knock-over plate keeps the new loops from sliding off the hook. The reverse rotation of the needle shifts the weft loops to the shank of the needle as it slowly begins its rearward movement. These movements permit a relatively rapid operation of the machine with minimum danger of malfunction of the needles in catching and knitting the weft yarns.

I claim:

1. In combination with a narrow-web loom having warp-forming means, a weft-laying finger and means for operating said finger to project successive loops of weft yarn across the warp from the near side to the far side thereof, a rigid open hook mounted at said far side of the Warp to receive the end of each said loop of weft yarn and to knit each received loop through the previously received loop, means for alternately advancing said hook to a position to take a weft loop from said finger and retracting said hook to a position for casting off the previously received loop, means for rotating said hook back and forth through ISO-degree turns in timed relation to the movements of said finger, and a knock-over element laterally spaced from the path of motion of said hook and in a position to be passed by said hook shortly before the hook reaches its fully retracted position.

2. The combination described in claim 1, plus a second weft-laying finger for projecting weft loops across the warp from said far side alternating with the projecting movements of the first said finger, and means for catching and knitting weft loops from said second finger, said last mentioned means comprising a second rigid open hook mounted at said near side of the warp to receive the end of each loop of weft yarn projected across the warp by said second weft-laying finger, means for-alternately advancing said second hook to a position to take a weft loop from said second finger and retracting said second hook to a position for casting off a previously received loop, means for rotating said second book back and forth through ISO-degree turns in timed relation to the movements of said second finger, and a knockover element laterally spaced from the path of motion of said second hook and in a position to be passed by said second hook shortly before the hook reaches its fully retracted position.

3. The combination described in claim 2, plus presser elements for engaging the weft yarn near the end of the respective fingers, to move the weft yarns into the paths of the respective cooperating hooks, and means operating said presser elements in timed relation to the movements of said hooks.

4. The combination described in claim 1, said hook having a back, a beak and a throat between the back and beak, said back, beak and throat being inclined forward and upward.

5. The combination described in claim 4, the end portion of said hook adjacent to said beak having a slight lateral reverse bend.

6. A method of forming a locked selvage on a narrow web in the course of weaving the same, comprising projecting across the warp alternate loops of Weft yarns from opposite sides thereof, catching the end of each projected loop on a rigid hook having its beak facing away from the warp, simultaneously retracting the hook pasta knockover element and rotating it half a turn, said rotation being completed just before the hook passes said knockover element, and pressing the other weft yarn into the hook whereby to knit both yarns through the previously caught loops of yarn, and then reversely rotating the hook half .a turn and advancing the hook axially to its loop-catching position, said reverse rotation being substantially completed before the hook has moved beyond said knock-over element.

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTS Germany. Great Britain.

DONALD W. PARKER, Primary Examiner.

J. KEE CHI, Assistant Examiner. 

1. IN COMBINATION WITH A NARROW-WEB LOOM HAVING WARP-FORMING MEANS, A WEFT-LAYING FINGER AND MEANS FOR OPERATING SAID FINGER TO PROJECT SUCCESSIVE LOOPS OF WEFT YARN ACROSS THE WARP FROM THE NEAR SIDE OF THE FAR SIDE THEREOF, A RIGID OPEN HOOK MOUNTED AT SAID FAR SIDE OF THE WARP TO RECEIVE THE END OF EACH SAID LOOP OF WEFT YARN AND TO KNIT EACH RECEIVED LOOP THROUGH THE PREVIOUSLY RECEIVED LOOP, MEANS FOR ALTERNATELY ADVANCING SAID HOOK TO A POSITION TO TAKE A WEFT LOOP FROM SAID FINGER AND RETRACTING SAID HOOK TO A POSITION FOR CASTING OFF THE PREVIOUSLY RECEIVED LOOP, MEANS FOR ROTATING SAID HOOK BACK AND FORTH THROUGH 180-DEGREES TURNS IN TIMED RELATION TO THE MOVEMENTS OF SAID FINGER, AND A KNOCK-OVER ELEMENT 